A. Field of the Invention
The present invention relates generally to compositions that can be used to improve the skin's condition and/or visual appearance. In certain aspects, the compositions of the present invention can include, for example, a combination of ingredients to reduce fine lines and wrinkles, counter oxidative damage, reduce oxidizing agents, increase production of dermal proteins (such as collagen and elastin), reduce red blotches, reduce pigmentation in cells, inhibit tyrosinase, inhibit melanogenesis, and/or inhibit TNF-α. In other aspects, a combination of ingredients can reduce inflammation, increase moisture, reduce skin irritation, reduce dark circles in or under the eyes, inhibit MMP1, inhibit COX-1, inhibit COX-2, inhibit lipoxygenase, increase elastin production, increase collagen stimulation, increase laminin production, and/or reduce permeability of skin cells. This combination of ingredients can be included in a wide-range of product formulations (e.g., serums, eye creams, day creams, night creams, cleansers, toners, gels, masks, etc.).
B. Description of Related Art
Aging, chronic exposure to adverse environmental factors, malnutrition, fatigue, etc., can change the visual appearance, physical properties, or physiological functions of skin in ways that are considered visually undesirable. The most notable and obvious changes include the development of fine lines and wrinkles, loss of elasticity, increased sagging, loss of firmness, loss of color evenness or tone, coarse surface texture, and mottled pigmentation. Less obvious but measurable changes which occur as skin ages or endures chronic environmental insult include a general reduction in cellular and tissue vitality, reduction in cell replication rates, reduced cutaneous blood flow, reduced moisture content, accumulated errors in structure and function, alterations in the normal regulation of common biochemical pathways, and a reduction in the skin's ability to remodel and repair itself. Many of the alterations in appearance and function of the skin are caused by changes in the outer epidermal layer of the skin, while others are caused by changes in the lower dermis.
Many factors contribute to skin aging and the appearance of aging such as the actual age of a person, the amount of exposure to environmental factors (e.g., sun light, pollution, chemicals, smoke, etc.), and how well a person has taken care of their skin. In particular, skin aging concerns two processes—intrinsic aging, which is related to the natural aging process and genetic influences, and extrinsic aging, which is accumulated damage due to environmental factors.
Intrinsic aging process in cells and skin can be related to the loss of proper function of the skin in maintaining biochemical pathways. Such pathways can control the oxidative/reductive environment balance in the skin, the regulation of cell division and cellular membrane integrity, and the maintenance of the moisture balance of the skin. As one example, intrinsic aging can be due to the function of the protein Lamin A, which is important during cell division as it provides the membrane structure of the nuclease. Without functional Lamin A, the nuclear lamina creates an abnormal nuclear envelope lacking structural support. This can lead to an abnormal shaped nuclear envelope which limits cell division. A muted form of Lamin A, known as progerin, is associated with the disease progeria where patients suffer from accelerated aging, displaying signs of aging in skin as early as 2 years of age, and have a sharply shortened lifespan. This, and other losses of proper function of the skin can lead to loss of skin firmness, increased skin unevenness, increased fine lines and wrinkles, increased oxidative damage, and dry skin.
Extrinsic factors can include exposure to ultraviolet (UV) rays, irritants, and pollution. UV rays, through sun exposure or the use of ultraviolet lamps (for example, tanning beds), can induce oxidative stress, inflammation, production of melanin, and even genetic mutations that leads to skin damage. The accumulation of oxidative stress through free radical formation can damage skin proteins leading to skin aging, which includes loss of elasticity, loss of dermal proteins, lines and wrinkles, and abnormal pigmentation. Inflammation is also a characteristic of UV and environmental damage. Inflammation can occur through inflammatory cytokines such as TNF-α, or enzymes that contribute to the inflammatory pathway such as cyclooxygenase 1 (COX-1), cyclooxygenase 2 (COX-2), and lipoxygenase. As inflammation persists, enzymes such as matrix metalloproteinase-1 (MMP1), matrix metalloproteinase-3 (MMP3), and matrix metalloproteinase-9 (MMP9) are involved in the breakdown of dermal proteins, which allows immune cells to migrate. This breakdown in dermal proteins such as laminin, elastin, and collagen can lead to skin aging. When exposed to extrinsic factors, the keratinocyte (outermost cell of the skin) releases signaling molecules, such as α-melanocyte-stimulating hormone (α-MSH), and inflammatory cytokines. These hormones trigger melanocytes to produce melanin (melanogenesis). Tyrosine is converted to melanin in a two-step process that includes the use of the tyrosinase enzyme. The production of melanin can result in variations in the color of the skin. For example, a person's skin can have a sallow tone or hyperpigmented spots. Conventional depigmenting agents, such as hydroquinone, corticosteroids, and kojic acid can raise several safety concerns (for example, ochronosis, atrophy, carcinogenesis, and other local or systemic side effects) with long-term exposure.
Extrinsic factors can also reduce the moisture in skin. Exposure to chemicals, solvents, washing, cosmetics, fabrics, or dry environments are some of the many ways that skin can lose moisture. Loss of moisture can lead to breaks or fine lines and wrinkles in the skin.
The combination of intrinsic and extrinsic factors eventually leads to visible signs of aging. Current products on the market either do not effectively address the signs or causes of aging or the effects of extrinsic factors on the skin and/or they have skin irritating effects. For example, current products may not address loss of skin firmness, pigmentation problems, appearance of fine lines or wrinkles, and/or loss of moisture.